Ambient air injector for air curtain stability

ABSTRACT

A refrigeration system comprises a display case having an exterior and an interior, the interior comprising a top surface, a bottom surface, a back area and a front viewing area at least partially defining a display space. A cooling element cools air within the display space. A first air outlet on the display case guides the cool air across the front viewing area along a first path. A second air outlet on the display case guides warm air across the viewing area along a second path wherein the second air outlet comprises an opening from the exterior to the interior of the display case. An air mover communicates with the cooling element directing air to the first air outlet.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a refrigerator display case.

[0002] A refrigeration display case typically has an air curtain that extends over the front viewing area of the case. A fan panel draws air into an air inlet near the bottom of the viewing area and then passes the air through a duct to a refrigeration coil, which cools the air. The cooled air then continues up the back of the display case through a vertical duct and then passes through another duct to an air outlet at the top of the viewing area. The air outlet directs the cooled air in the form of an air curtain back to the air inlet at the bottom of the viewing area, completing a cooling circuit. The air curtain helps retain cool air in the display space of the display, thereby cooling the display product on the shelves of the display case.

[0003] Warm ambient air outside the display case frequently intrudes into the path of the air curtain. As a consequence, the refrigerated display case must work hard to maintain the temperature within the display space. Systems do exist that seek to address the problem of warm air incursion. One such system employs three separate cooling circuits to form a multi-layered and multi-temperature air curtain. The layer closest the interior of the display space is coolest while the layer furthest away is warmest. The warm air layer serves to buffer the cool air layer from warm air intrusion by redirecting the intruding warm air along the path of the air curtain rather than against it.

[0004] Each layer of air is formed by separate cooling circuits that extend through the display case. Each circuit has its own air inlet located at the bottom of the viewing area. A fan panel draws air into each air inlet and channels this air through separate ducts to connected air outlets at the top of the viewing area. As air passes through each cooling circuit, it warms to a differing degree depending upon the proximity of the circuit to the exterior of the display case—the cooling circuit closest the exterior is warmest while the circuit closest the interior is coolest. Each air outlet then blows air from its circuit across the viewing area to form the multi-layer and multi-temperature air curtain. However, while these multiple circuits may help improve the quality of the air curtain, they are expensive because of the separate duct work required for each circuit.

[0005] A need exists for a refrigeration system that addresses the problem encountered by the interaction of warm air outside of the display case and the air curtain without significant expense.

SUMMARY OF THE INVENTION

[0006] The inventive refrigeration system employs a display case having a first air outlet that directs cool air across a viewing area of the display case. In addition to the first air outlet, a second air outlet works with the first air outlet to guide warm air across the same viewing area. In contrast to existing refrigeration display cases, the second air outlet comprises a simple opening extending from the exterior of the display case to the interior, rather than a separate cooling circuit that runs through the entire display case. The design is accordingly less expensive than other multi-layer air curtain display cases. Moreover, the second outlet may work passively to guide air across the viewing area rather than through a fan panel, thereby reducing energy consumption.

[0007] The display case has a top, bottom, and a front viewing area that outlines in part the display space. A cooling element cools air for the display space. The first outlet receives cool air from the cooling element and guides the air across the viewing area along a first path. A second outlet on the display case guides air having a different temperature across the viewing area along a second path from an exterior of the display case to an interior. The temperature of the air from the first air outlet may be cool and form a cool air curtain while the temperature of air from the second air outlet may be warm and form a warm air curtain. Air may be directed from both outlets along the same path and along the same direction. The cool air curtain is preferably closer to the display space than the second path, permitting the warm air curtain to insulate the cool air curtain from the effects of warm air outside the display case.

[0008] The second outlet may comprise an opening at the top of the display case. The opening may comprise a first mouth spaced from a second mouth by a channel. The first mouth may be larger than the second month to create a nozzle like effect and thereby promote movement of air over the front viewing area.

[0009] Air may be directed within the display case by fan, electric induction, or any other device commonly available to move air. The device may move air from top to bottom of the display space and may further draw air to a warm air return at the bottom of the display case. Air may simply be drawn from the top of the display case by the entrainment effects of the cool air curtain.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:

[0011]FIG. 1 illustrates a side profile of the inventive refrigeration display case, showing a warm air curtain and a cool air curtain directed across a viewing area of the case.

[0012]FIG. 2 illustrates a perspective view of the inventive refrigeration system, showing product on the shelves of the system.

[0013]FIG. 3 illustrates a close-up view of the two outlets of the inventive display case that direct air across the viewing area of the display case.

[0014]FIG. 4 illustrates a foil used to direct air around an air inlet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015]FIG. 1 illustrates inventive refrigeration system 10. Refrigeration system 10 comprises display case 14, which has exterior 21 and interior 23. Interior 23 comprises display space 30 having top surface area 18, bottom surface area 22, back surface area 20, and front viewing area 26. Front viewing area 26 extends from top surface area 18 to bottom surface area 22 and helps define display space 30 along with back surface area 20, as shown. Exterior 21 extends around interior 23 and is spaced from interior 23 to permit components of a refrigeration system to fit between exterior 21 and interior 23 as known and as described below.

[0016] Within the confines of display case 14, between exterior 21 and interior 23, cooling element 34, such as a refrigeration coil, serves to cool air within display space 30. Air mover 54 serves to direct air from air inlet 64, a warm air return, across cooling element 34 up duct 68 to first air outlet 38. First air outlet 38 directs cool air along first path 42 to air inlet 64, permitting air to be recycled through refrigeration system 10. Of course, air inlet 64 may include a good deal of air from air curtain 48 as well as air curtain 51. Through this cooling circuit, cool air curtain 51 is formed across viewing area 26 from top surface 18 to bottom surface 22. Air may be cycled through refrigeration system 10 by air mover 54, such as a generally available commercial air blower, fan panel, electric induction device, or other known devices.

[0017] As shown in FIGS. 1-3, refrigeration system 10 has first air outlet 38 and second air outlet 46. In contrast to existing refrigeration systems, second air outlet 46 serves to guide warm air along second path 50 across viewing area 26. Warm air curtain 48 is formed outside, i.e. further away from interior 23, of cool air curtain 51 to serve to insulate display space 30 from the effects of ambient warm air moving across the path of cool air curtain 51, say along the direction of arrow A. Hence, warm air curtain 48 serves to buffer cool air curtain 51 from the effects of air directed at cool air curtain 51. In this way, refrigeration system 10 serves to conserve energy.

[0018]FIG. 3 shows in detail first air outlet 38 and second air outlet 46. As shown, first air outlet 38 and second air outlet 46 are located at top surface area 18 of display case 14. Second air outlet 46 maybe located closer to front 15 of display case 14 than back 17 of display case 14. As shown in FIG. 1, first air outlet 38 is in communication with duct 68 and blows cool air across front viewing area 26 as driven by air mover 34. In contrast to known refrigerated display cases, as shown in FIG. 3, second air outlet 46 comprises opening 60 extending from exterior 21 to interior 23 of display case 14. Opening 60 may comprise a vent that serves to draw warm ambient air, say along arrow B, outside of exterior 21 to be guided into interior 23 along second path 50. Opening 60 may have first mouth 19 and second mouth 27 spaced from first mouth 19 by channel 61. Mouth 19 may have width W₁ larger than width W₂ of month 27. Channel 61 may thus taper from mouth 19 to mouth 27 to create a nozzle like shape and thereby promote the movement of air through channel 61 from mouth 19 out mouth 27 through a Venturi effect. Air is drawn into opening 60 because of the entrainment effects created by air curtain 51, which creates a low-pressure region at point Z to draw air into opening 60 and interior 23. In this way, the inventive refrigeration system 10 may passively (without fan or other air mover) create warm air curtain across front viewing area 26.

[0019] As shown in FIG. 1, spaced from first air outlet 38 and second air outlet 46 on the other side of front viewing area 26 is foil 63. As shown in FIG. 4, foil 63 may have first side 77 and second side 79. First side 77 serves to redirect warm air curtain 48 along second path 50 along arrow C while second side 79 serves to redirect cool air curtain 51 along path 48 along arrow D into air inlet 64. In this way, cool air from cool air curtain 51 is returned to cooling element 34 and warm air from air curtain is kept away from cooling element 34 to limit energy consumption by refrigeration system 10.

[0020] The aforementioned description is exemplary rather that limiting. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed. However, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. Hence, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For this reason the following claims should be studied to determine the true scope and content of this invention. 

What is claimed is:
 1. A refrigeration system comprising; a display case having an exterior and an interior, said interior comprising a top surface, a bottom surface, a bottom surface, a back area and a front viewing area, at least partially defining a display space; a cooling element, cooling air within said display space; a first air outlet on said display case, communicating with said cooling element, guiding air having a first temperature across said front viewing area along a first path; a second air outlet on said display case for guiding air having a second temperature across said viewing area along a second path wherein said second air outlet comprises an opening from said exterior to said interior of said display case; and an air mover in communication with said cooling element directing air to said first air outlet.
 2. The refrigeration system of claim 1 wherein said first temperature is generally lower than said second temperature.
 3. The refrigeration system of claim 1 wherein said first path is generally along said second path.
 4. The refrigeration system of claim 1 wherein said first path and said second path are generally in the same direction.
 5. The refrigeration system of claim 1 wherein said first path is closer to said display space than said second path.
 6. The refrigeration system of claim 1 wherein said opening comprises a channel extending between said interior and said exterior, said channel having a first month on said exterior and a second month on said interior.
 7. The refrigeration system of claim 6 wherein said channel extends to said top surface.
 8. The refrigeration system of claim 6 wherein said first mouth has a larger width than said second mouth.
 9. The refrigeration system of claim 8 wherein said channel is tapered.
 10. A refrigeration system comprising: a display case having an exterior and an interior, said interior comprising a top surface, a bottom surface, a back area and a front viewing area at least partially defining display surface; a cooling element for cooling air about said display space; at least a first air mover for directing air across said cooling element; a first air outlet in communication with said at least first air mover for guiding air having a first temperature across said display space along a first path; and a second air outlet for guiding air having a second temperature across said display space along a second path wherein said first temperature is generally lower than said second temperature and wherein said first path is generally along said second path, and wherein said second air outlet comprises an opening from said exterior to said interior of said display case, said opening comprising a first mouth, a second mouth and a channel spaced from said first mouth and said second mouth, said first mouth larger than said second mouth.
 11. The refrigeration system of claim 10 wherein said first path and said second path are generally in the same direction.
 12. The refrigeration system of claim 10 wherein said first path is closer to said display space than said second path.
 13. The refrigeration system of claim 10 wherein said first air outlet is spaced across said display space from an air inlet in communication with said cooling element.
 14. The refrigeration system of claim 13 including a foil directing air from said first air outlet to said air inlet and air from said second air outlet away from said air inlet.
 15. The refrigeration system of claim 14 wherein said foil has a first side and a second side, said first side directing air away from said air inlet and said second side directing air to said air inlet.
 16. The refrigeration system of claim 10, wherein said channel extends to said top surface.
 17. The refrigeration system of claim 10, wherein said channel is tapered.
 18. A refrigeration system comprising: a display case having an exterior and an interior, said interior comprising a top surface, a bottom surface, a back area and a front viewing area of at least partially defining a display space; a cooling element for cooling air about said display space; at least a first air mover for directing air across said cooling element; a first air outlet in communication with said at least first air mover for guiding air having a first temperature across said display space along a first path; a second air outlet for guiding air having a second temperature across said display space along a second path wherein said first temperature is generally lower than said second temperature, wherein said first path is generally along said second path and in the same direction; and wherein said second air outlet comprises a channel extending between said exterior surface and said top surface.
 19. The refrigeration system of claim 18, wherein said first path is closer to said display space than said second path.
 20. The refrigeration system of claim 18, including a foil directing air from said first air outlet to an air inlet and air from said second air outlet away from said air inlet. 